During a mobile phone calibration, power amplifier input power is swept to a power level as high as 10 dBm and to a maximum supply voltage of from 4-5 V. This combination of high drive level and power supply voltage can result in a peak output power 3-4 dB above normal operating conditions and collector voltages above the safe operating range of the device technology used. This puts the power amplifier at risk of being damaged and puts surface acoustic wave or bulk acoustic wave duplex filters at risk of being damaged. Exacerbating the problem is the fact that filters are being aggressively reduced in size, which limits their maximum safe power dissipation. Additionally, envelope trackers are now commonly implemented into mobile phones. Most, if not all, envelope trackers have a boost mode that can raise the maximum power amplifier supply voltage to as high as 5.5 V. Up until now, this problem has not been properly addressed as it pertains to differential power amplifiers. Thus, there is a need for new differential power amplifier that includes protective circuitry.